Answer
Find out the ratio of sharpened pencils to unsharpened pencils .
To proof
As given
In a box of 36 pencils, 20 are sharpened
Number of unsharpened pencil = 36 -20
= 16
Now find out the ratio of sharpened pencils to unsharpened pencils .
\(\frac{sharpened\ pencil}{unsharpened\ pencil} = \frac{20}{16}\)
simplify
\(\frac{sharpened\ pencil}{unsharpened\ pencil} = \frac{5}{4}\)
Therefore the ratio of sharpened pencils to unsharpened pencils is 5 :4 .
Hence proved
